GB907265A - Improvements in and relating to the treatment of solid free flowing, pulverulent materials - Google Patents

Abstract

907,265. Removing solvent from solventextracted meal. CENTRAL SOYA CO. Inc. Oct. 27, 1959, No. 36483/59. Class 58. In treating solid, pulverulent, free-flowing material, e.g. to remove residual solvent such as hexane from solvent-extracted meal such as soybean flakes, the material is fed into a kettle A through an inlet 12 in its vapour dome 11 and then moves downwardly and continuously through kettles B, C, D and E. A casing 10, which may be heated by steam tubes or a steam jacket, constitutes the dome 11 and encloses the kettles. The kettles have hollow floors 25, 27, 29, 32 and 34, which are heated by admitting steam into their cavities. The material passes from kettle A into kettle B through an annular space between the casing and the floor 25, leaving a space 25a under the latter, and passes from kettle B into kettle C through a central opening in the floor 27. Steam is passed upwardly through the material in the kettle C from perforations in the upper surface of its hollow floor 29, which constitutes a sparging plate. The steam, e.g. containing solvent vapour, passes from the inclined face 64, of this material, through an annular space 63 and openings between louvres 60, into and through the material in kettles B and A. The steam, e.g. containing solvent vapour, passes from the material in kettle A through the dome 11, a scrubber 15 and a pipe 16 into a condenser (not shown). The material passes from kettle C into kettle D through an annular space between the casing and the floor 29, leaving a space 28a under the latter, and then passes successively into the three kettles E, through downwardly widening passages 35 in the floors 32 and 34, and is discharged from the lowermost kettle E through a gate-valve 38 and a helical conveyer 59. Apertures 45 covered by screens are provided in the floors 32 and 34 to allow upward passage of vapour from the material. A vertical shaft 19 carrying horizontal sweeping arms 40, 41, 43 and 44 is provided within the casing and is rotated, through reduction gear 22, by a motor 23. A flat member 49 riding on the material in the kettle A actuates a crank 50 turning a shaft 51 passing through a sealed bearing in the casing. A crank 53, on the outer end of the shaft, is connected to a tie rod 54, which engages a lever 55 controlling a variablespeed drive or motor 56 driving the conveyer 59. When the material in kettle A drops below or rises above a desired level, discharge from the lowest kettle E is reduced or speeded up to restore the desired level. Specification 720,184 is referred to.